EP0014431B1 - Process for the recovery of fluorinated emulsifying acids from basic ion exchangers - Google Patents

Process for the recovery of fluorinated emulsifying acids from basic ion exchangers Download PDF

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Publication number
EP0014431B1
EP0014431B1 EP80100470A EP80100470A EP0014431B1 EP 0014431 B1 EP0014431 B1 EP 0014431B1 EP 80100470 A EP80100470 A EP 80100470A EP 80100470 A EP80100470 A EP 80100470A EP 0014431 B1 EP0014431 B1 EP 0014431B1
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Prior art keywords
acid
acids
fluorinated
elution
fluorinated emulsifier
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EP0014431A3 (en
EP0014431A2 (en
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Jürgen Dr. Kuhls
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Hoechst AG
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Hoechst AG
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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F6/00—Post-polymerisation treatments
    • C08F6/14—Treatment of polymer emulsions
    • C08F6/16—Purification
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J47/00—Ion-exchange processes in general; Apparatus therefor
    • B01J47/014—Ion-exchange processes in general; Apparatus therefor in which the adsorbent properties of the ion-exchanger are involved, e.g. recovery of proteins or other high-molecular compounds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J49/00—Regeneration or reactivation of ion-exchangers; Apparatus therefor
    • B01J49/05—Regeneration or reactivation of ion-exchangers; Apparatus therefor of fixed beds
    • B01J49/07—Regeneration or reactivation of ion-exchangers; Apparatus therefor of fixed beds containing anionic exchangers
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/42—Separation; Purification; Stabilisation; Use of additives
    • C07C51/47—Separation; Purification; Stabilisation; Use of additives by solid-liquid treatment; by chemisorption

Definitions

  • the invention relates to a method for the elution of fluorinated emulsifier acids adsorbed on basic anion exchangers.
  • fluorinated emulsifiers can be used successfully for the polymerization of fluorinated monomers in aqueous dispersion because of the telogen inactivity required.
  • these are primarily the salts, preferably the alkali or ammonium salts of perfluorinated or partially fluorinated alkanoic acids or also of perfluorinated or partially fluorinated alkanesulfonic acids.
  • the production of such fluorinated emulsifiers by the process of electrofluorination or by the telomerization of fluorinated monomers is associated with high costs, which in turn cause the high price of such fluorinated emulsifiers.
  • DE-C 20 44 986 describes a process for the adsorption of perfluorocarboxylic acids or their salts from the aqueous serum of precipitated polytetrafluoroethylene dispersions with the aid of weakly basic anion exchangers. According to this method, the subsequent elution of the adsorbed fluorinated emulsifier should take place using a dilute, aqueous ammonia solution.
  • the present invention was therefore based on the task of significantly reducing the amount of eluent required for the elution and thus also the time required and also regenerating the anion exchanger in the same operation for the renewed adsorption of the fluorinated emulsifier acids.
  • This object is achieved according to the present invention in that the elution of the adsorbed fluorinated emulsifier acid from the anion exchanger is carried out with a mixture of dilute mineral acid and an organic solvent.
  • fluorinated emulsifier acids can also be eluted by the process according to the invention. Mixtures of the fluorinated emulsifier acids mentioned can also be adsorbed and eluted, especially those containing perfluorooctanoic acid as the main ingredient.
  • the fluorinated emulsifier acids mentioned are usually added to the anion exchanger in the solutions to be worked up in the form of their salts, in particular their alkali metal and ammonium salts, for adsorption.
  • These solutions to be worked up can also contain fluoride ions as well as other dispersants, such as nonionic oxalkylates of alcohols or phenols, without this hindering the recovery of the fluorinated emulsifier acids by the process according to the invention.
  • Mineral acids are all those whose anions give the anion exchanger a salt form (anion form) which is suitable for the further adsorption of fluorinated emulsifier acids. Their oxidation strength under the conditions of the elution should be so low that the anion exchanger is not oxidatively damaged.
  • Suitable mineral acids are, for example, ortho-, meta- or diphosphoric acid, nitric acid and preferably hydrochloric acid and sulfuric acid.
  • organic solvents which do not damage the function of the anion exchanger used, for example by swelling or dissolving, or which do not react with the mineral acid used, are suitable as organic solvents in the acidic system used.
  • Such solvents can be polar organic solvents such as chlorinated hydrocarbons, aliphatic or aromatic ethers and carboxylic acid esters.
  • solvents which can be mixed without limits such as preferably aliphatic alcohols having 1 to 4 carbon atoms, in particular methanol or ethanol, cyclic ethers such as tetrahydrofuran or dioxane, short-chain, dialkyl-substituted amides such as dimethylformamide or dimethylacetamide or also mono- or dimethyl- or mono- or diethyl ether of ethylene glycol or the corresponding polyglycols up to the chain length of the decaethylene glycol. Mixtures of such solvents can also be used.
  • a mixture is set from the mineral acid used in each case and the organic solvent, the acid strength of which, based on the total mixture, is 0.5 to 10 n, preferably 0.5 to 2 n.
  • the ratio of mineral acid (including the water content) to organic solvent in this mixture is 1: 0.25 to 1:20, preferably 1: 3 to 1:10 parts by volume.
  • weakly basic anion exchangers which contain primary, secondary, but preferably tertiary amino groups in the form of the ammonium salts (for example types MP 62 from Bayer AG, Leverkusen, or IRA 68 from Serva, Heidelberg).
  • strongly basic anion exchangers which generally have quaternary ammonium groups (for example type M 600 from Bayer AG, Leverkusen), are also suitable.
  • these strongly basic anion exchangers generally only have sufficient adsorption capacity in the OH form for the emulsifier acids or their salts to be adsorbed and must therefore be converted back to the OH form after the elution has ended by adding strong bases, such as, for example, sodium hydroxide solution .
  • an amount of 50 to 500, preferably 100 to 225 parts by volume, based on 100 parts by volume of the anion exchanger filling, of the mixture of mineral acid and organic solvent is generally required.
  • the eluate After elution has ended, the eluate generally separates into two layers, the heavier, lower layer containing practically all of the fluorinated emulsifier acid. This is neutralized with dilute, usually about 2 N sodium hydroxide solution and then precipitated by stirring in dilute hydrochloric acid in a compact and easily separable form.
  • the temperature during the elution according to the method according to the invention is not critical.
  • the elution should expediently be carried out at room temperature, that is to say in the temperature range from 15 to 25.degree.
  • the process according to the invention has significant advantages over the known elution with dilute, aqueous ammonia solution.
  • Table I the amount of eluent required can be drastically reduced, thus shortening the time required for the anion exchanger to discharge.
  • the yield of recovered fluorinated emulsifier acid is increased. In many cases it is almost quantitative.
  • dilute inorganic mineral acids in a mixture with organic solvents when a weakly basic anion exchanger is used, this is converted back into its original salt form during the elution. This saves the otherwise necessary separate regeneration of such a weakly basic anion exchanger into the salt form by means of dilute mineral acid after each elution step.
  • fluorinated emulsifier acids The removal and recovery of fluorinated emulsifier acids is particularly important in the case of aqueous solutions which are involved in precipitation and coagulation processes in the course of working up emulsion polymers of fluorine-containing monomers, that is, above all homopolymers and copolymers of tetrafluoroethylene, vinylidene fluoride, vinyl fluoride and trifluorochloroethylene, but also of aqueous emulsion obtained fluorocarbon telomer waxes.
  • the separation and recovery of fluorinated emulsifier acids can also be carried out from aqueous solutions which are obtained in the concentration processes of fluoropolymer latexes, in particular in those concentration processes which proceed with delamination.
  • inorganic salts or nonionic dispersants such as, for example, alkoxylated alkylphenols or alkoxylated aliphatic alcohols or alkylene oxide block polymers, are present in such aqueous solutions, they do not interfere with the adsorption and also the elution.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Polymers & Plastics (AREA)
  • Medicinal Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Emulsifying, Dispersing, Foam-Producing Or Wetting Agents (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)
  • Treatment Of Liquids With Adsorbents In General (AREA)
  • Colloid Chemistry (AREA)

Description

Die Erfindung betrifft ein Verfahren zur Elution von an basischen Anionenaustauschern adsorbierten fluorierten Emulgatorsäuren.The invention relates to a method for the elution of fluorinated emulsifier acids adsorbed on basic anion exchangers.

Für die Polymerisation fluorierter Monomerer in wäßriger Dispersion können wegen der erforderlichen telogenen Inaktivität im allgemeinen nur fluorierte Emulgatoren mit Erfolg eingesetzt werden. Dies sind vor allem die Salze, vorzugsweise die Alkali- oder Ammoniumsalze von perfluorierten oder teilfluorierten Alkansäuren oder auch von perfluorierten oder teilfluorierten Alkansulfonsäuren. Die Herstellung solcher fluorierter Emulgatoren durch den Prozeß der Elektrofluorierung oder durch die Telomerisation fluorierter Monomerer ist mit hohen Kosten verbunden, die wiederum den hohen Preis solcher fluorierter Emulgatoren bedingen. Es ist daher von besonderer Bedeutung, zur Einsparung von Kosten den in der nach der Koagulation des Polymeren aus der Dispersion oder bei der Aufkonzentrierung wäßriger Polymerdispersionen in der wäßrigen Phase gelösten Anteil an fluoriertem Emulgator zurückzugewinnen. Die kann besonders vorteilhaft durch Adsorption mit Hilfe von Ionenaustauschern und deren anschließende Elution bewirkt werden.In general, only fluorinated emulsifiers can be used successfully for the polymerization of fluorinated monomers in aqueous dispersion because of the telogen inactivity required. These are primarily the salts, preferably the alkali or ammonium salts of perfluorinated or partially fluorinated alkanoic acids or also of perfluorinated or partially fluorinated alkanesulfonic acids. The production of such fluorinated emulsifiers by the process of electrofluorination or by the telomerization of fluorinated monomers is associated with high costs, which in turn cause the high price of such fluorinated emulsifiers. It is therefore of particular importance, in order to save costs, to recover the proportion of fluorinated emulsifier dissolved in the aqueous phase after the coagulation of the polymer from the dispersion or in the concentration of aqueous polymer dispersions. This can be effected particularly advantageously by adsorption with the aid of ion exchangers and their subsequent elution.

In der DE-C 20 44 986 ist ein Verfahren zur Adsorption von Perfluorcarbonsäuren bzw. deren Salzen aus dem wäßrigen Serum gefällter Polytetrafluorethylen-Dispersionen mit Hilfe von schwach basischen Anionenaustauschern beschrieben. Nach diesem Verfahren soll die anschließende Elution des adsorbierten fluorierten Emulgators unter Verwendung einer verdünnten, wäßrigen Ammoniaklösung erfolgen.DE-C 20 44 986 describes a process for the adsorption of perfluorocarboxylic acids or their salts from the aqueous serum of precipitated polytetrafluoroethylene dispersions with the aid of weakly basic anion exchangers. According to this method, the subsequent elution of the adsorbed fluorinated emulsifier should take place using a dilute, aqueous ammonia solution.

Dieses Verfahren besitzt zwei wesentliche Nachteile. Erstens werden für die vollständige Elution relativ große Mengen an verdünnter NH40H-Lösung benötigt. Zum andern ist der Zeitbedarf zur Erreichung dieses Ziels zu hoch. Außerdem müssen die Ionenaustauscher nach beendetem Elutionsschritt in einem angeschlossenen Regenerierprozeß mit verdünnter Mineralsäure wieder in die für die erneute Adsorption der im allgemeinen in Salzform vorliegenden fluorierten Emulgatoren besonders geeignete Anionenform, insbesondere die Chloridform, übergeführt werden.This process has two major disadvantages. First, relatively large amounts of dilute NH 4 0H solution are required for complete elution. Secondly, the time required to achieve this goal is too long. In addition, after the elution step has ended, the ion exchangers must be converted back into the regeneration process with dilute mineral acid into the anion form which is particularly suitable for the re-adsorption of the fluorinated emulsifiers which are generally in salt form, in particular the chloride form.

Der vorliegenden Erfindung lag daher die Aufgabe zugrunde, die für die Elution benötigte Menge an Elutionsmittel und damit auch den Zeitaufwand wesentlich zu reduzieren und ferner den Anionenaustauscher im gleichen Arbeitsgang für die erneute Adsorption der fluorierten Emulgatorsäuren zu regenerieren.The present invention was therefore based on the task of significantly reducing the amount of eluent required for the elution and thus also the time required and also regenerating the anion exchanger in the same operation for the renewed adsorption of the fluorinated emulsifier acids.

Diese Aufgabe wird gemäß der vorliegenden Erfindung dadurch gelöst, daß die Elution der adsorbierten fluorierten Emulgatorsäure aus dem Anionenaustauscher mit einem Gemisch aus verdünnter Mineralsäure und einem organischen Lösungsmittel vorgenommen wird.This object is achieved according to the present invention in that the elution of the adsorbed fluorinated emulsifier acid from the anion exchanger is carried out with a mixture of dilute mineral acid and an organic solvent.

Unter dem Begriff fluorierte Emulgatorsäuren sollen hier vor allem perfluorierte Alkansäuren der Formel CF3(CF2),COOH (n = 3 bis 10), insbesondere Perfluoroctansäure, verstanden werden, auf die das erfindungsgemäße Verfahren bevorzugt anwendbar ist. Unter diesen Begriff fallen aber auch teilfluorierte Alkansäuren der Formel XCF2(CF2)"COOH (X = H oder CI, n = 3 bis 10), perfluorierte oder teilfluorierte Alkansulfonsäuren der Formel XCF2(CF2)rSO3H (X = H oder vorzugsweise F, n = 3 bis 10) sowie Perfluor-[(ß-propoxy)-propionsäure]. Auch diese fluorierten Emulgatorsäuren können nach dem erfindungsgemäßen Verfahren eluiert werden. Es können auch Gemische der genannten fluorierten Emulgatorsäuren adsorbiert und eluiert werden, insbesondere solche, die Perfluoroctansäure als Hauptbestandteil enthalten.The term fluorinated emulsifier acids is to be understood here to mean above all perfluorinated alkanoic acids of the formula CF 3 (CF 2 ), COOH (n = 3 to 10), in particular perfluorooctanoic acid, to which the process according to the invention is preferably applicable. This term also includes partially fluorinated alkanoic acids of the formula XCF 2 (CF 2 ) " COOH (X = H or CI, n = 3 to 10), perfluorinated or partially fluorinated alkanesulfonic acids of the formula XCF 2 (CF 2 ) r SO 3 H (X = H or preferably F, n = 3 to 10) and perfluoro - [(β-propoxy) propionic acid] These fluorinated emulsifier acids can also be eluted by the process according to the invention. Mixtures of the fluorinated emulsifier acids mentioned can also be adsorbed and eluted, especially those containing perfluorooctanoic acid as the main ingredient.

Die genannten fluorierten Emulgatorsäuren werden dem Anionenaustauscher in den aufzuarbeitenden Lösungen üblicherweise in Form ihrer Salze, insbesondere ihrer Alkali- und Ammoniumsalze zur Adsorption aufgegeben. Diese aufzuarbeitenden Lösungen können daneben auch Fluoridionen, ebenso aber auch andere Dispergiermittel enthalten, wie z.B. nichtionische Oxalkylate von Alkoholen oder Phenolen, ohne daß dadurch die Rückgewinnung der fluorierten Emulgatorsäuren nach dem erfindungsgemäßen Verfahren behindert wird.The fluorinated emulsifier acids mentioned are usually added to the anion exchanger in the solutions to be worked up in the form of their salts, in particular their alkali metal and ammonium salts, for adsorption. These solutions to be worked up can also contain fluoride ions as well as other dispersants, such as nonionic oxalkylates of alcohols or phenols, without this hindering the recovery of the fluorinated emulsifier acids by the process according to the invention.

Als Mineralsäuren kommen alle diejenigen in Frage, deren Anionen dem Anionenaustauscher eine Salzform (Anionenform) verleihen, die für die weitere Adsorption von fluorierten Emulgatorsäuren geeignet ist. Ihre Oxidationsstärke unter den Bedingungen der Elution soll so gering sein, daß der Anionenaustauscher nicht oxidativ geschädigt wird. Geeignete Mineralsäuren sind beispielsweise Ortho-, Meta- oder Diphosphorsäure, Salpetersäure und vorzugsweise Salzsäure und Schwefelsäure.Mineral acids are all those whose anions give the anion exchanger a salt form (anion form) which is suitable for the further adsorption of fluorinated emulsifier acids. Their oxidation strength under the conditions of the elution should be so low that the anion exchanger is not oxidatively damaged. Suitable mineral acids are, for example, ortho-, meta- or diphosphoric acid, nitric acid and preferably hydrochloric acid and sulfuric acid.

Als organische Lösungsmittel kommen im Prinzip alle organischen Lösungsmittel in Betracht, die im verwendeten sauerwäßrigen System weder den eingesetzten Anionenaustauscher in seiner Funktion, beispielsweise durch Quellung oder Anlösen, schädigen noch mit der eingesetzten Mineralsäure unerwünschte Reaktionen eingehen. Derartige Lösungsmittel können polare organische Lösungsmittel sein, wie beispielsweise Chlorkohlenwasserstoffe, aliphatische oder aromatische Ether und Carbonsäureester. Bevorzugt sind jedoch mit Wasser weitgehend, das heißt bei Vermischung gleicher Volumina zu 40 bis 100 %, oder unbegrenzt mischbare Lösungsmittel, wie vorzugsweise aliphatische Alkohole mit 1 bis 4 C-Atomen, insbesondere Methanol oder Ethanol, cyclische Ether wie Tetrahydrofuran oder Dioxan, kurzkettige, dialkylsubstituierte Amide wie Dimethylformamid oder Dimethylacetamid oder auch Mono-oder Dimethyl- oder Mono- oder Diethylether des Ethylenglykols oder der entsprechenden Polyglykole bis zur Kettenlänge des Dekaethylenglykols. Es können auch Gemische solcher Lösungsmittel Verwendung finden.In principle, all organic solvents which do not damage the function of the anion exchanger used, for example by swelling or dissolving, or which do not react with the mineral acid used, are suitable as organic solvents in the acidic system used. Such solvents can be polar organic solvents such as chlorinated hydrocarbons, aliphatic or aromatic ethers and carboxylic acid esters. However, preference is given to a large extent with water, that is to say when the same volumes are mixed to 40 to 100%, or solvents which can be mixed without limits, such as preferably aliphatic alcohols having 1 to 4 carbon atoms, in particular methanol or ethanol, cyclic ethers such as tetrahydrofuran or dioxane, short-chain, dialkyl-substituted amides such as dimethylformamide or dimethylacetamide or also mono- or dimethyl- or mono- or diethyl ether of ethylene glycol or the corresponding polyglycols up to the chain length of the decaethylene glycol. Mixtures of such solvents can also be used.

Aus der jeweils eingesetzten Mineralsäure und dem organischen Lösungsmittel wird ein Gemisch eingestellt, dessen Säurestärke, bezogen auf das Gesamtgemisch, 0,5 bis 10 n, vorzugsweise 0,5 bis 2 n, ist. Das Verhältnis von Mineralsäure (einschließlich des Wasseranteils) zu organischem Lösungsmittel in diesem Gemisch beträgt 1 : 0,25 bis 1 : 20, vorzugsweise 1 : 3 bis 1 : 10 Volumenteile.A mixture is set from the mineral acid used in each case and the organic solvent, the acid strength of which, based on the total mixture, is 0.5 to 10 n, preferably 0.5 to 2 n. The ratio of mineral acid (including the water content) to organic solvent in this mixture is 1: 0.25 to 1:20, preferably 1: 3 to 1:10 parts by volume.

Für die der Elution vorangehende Adsorption der fluorierten Emulgatorsäuren werden vorzugsweise schwach basische Anionenaustauscher eingesetzt, die primäre, sekundäre, vorzugsweise aber tertiäre Aminogruppen in Form der Ammoniumsalze enthalten (beispielsweise die Typen MP 62 der Firma Bayer AG, Leverkusen, oder IRA 68 der Firma Serva, Heidelberg). Geeignet sind im Prinzip auch stark basische Anionenaustauscher, die in der Regel quaternäre Ammoniumgruppen besitzen (beispielsweise Typ M 600 der Firma Bayer AG, Leverkusen). Diese stark basischen Anionenaustauscher besitzen für die zu adsorbierenden Emulgatorsäuren bzw. deren Salze jedoch im allgemeinen nur in der OH-Form ein ausreichendes Adsorptionsvermögen und müssen daher nach beendeter Elution durch Zugabe von starken Basen, wie beispielsweise Natronlauge, wieder in die OH-Form übergeführt werden.For the adsorption of the fluorinated emulsifier acids preceding the elution, weakly basic anion exchangers are preferably used which contain primary, secondary, but preferably tertiary amino groups in the form of the ammonium salts (for example types MP 62 from Bayer AG, Leverkusen, or IRA 68 from Serva, Heidelberg). In principle, strongly basic anion exchangers, which generally have quaternary ammonium groups (for example type M 600 from Bayer AG, Leverkusen), are also suitable. However, these strongly basic anion exchangers generally only have sufficient adsorption capacity in the OH form for the emulsifier acids or their salts to be adsorbed and must therefore be converted back to the OH form after the elution has ended by adding strong bases, such as, for example, sodium hydroxide solution .

Für die vollständige Elution der adsorbierten Emulgatorsäuren wird im allgemeinen eine Menge von 50 bis 500, vorzugsweise 100 bis 225 Vol.-Teile, bezogen auf 100 Vol.-Teile an Füllung des Anionenaustauschers, der Mischung aus Mineralsäure und organischem Lösungsmittel benötigt.For the complete elution of the adsorbed emulsifier acids, an amount of 50 to 500, preferably 100 to 225 parts by volume, based on 100 parts by volume of the anion exchanger filling, of the mixture of mineral acid and organic solvent is generally required.

Nach beendeter Elution trennt sich das Eluat in der Regel in zwei Schichten, wobei die spezifisch schwerere, untere Schicht praktisch die gesamte fluorierte Emulgatorsäure enthält. Diese wird mit verdünnter, üblicherweise etwa 2 n Natronlauge neutralisiert und dann durch Einrühren in verdünnte Salzsäure in kompakter und leicht abtrennbarer Form ausgefällt.After elution has ended, the eluate generally separates into two layers, the heavier, lower layer containing practically all of the fluorinated emulsifier acid. This is neutralized with dilute, usually about 2 N sodium hydroxide solution and then precipitated by stirring in dilute hydrochloric acid in a compact and easily separable form.

Die Temperatur bei der Elution nach dem erfindungsgemäßen Verfahren ist nicht kritisch. Die Elution soll zweckmäßigerweise bei Raumtemperatur vorgenommen werden, also etwa im Temperaturbereich von 15 bis 25 °C, gelegentlich kann eine Temperaturerhöhung von Vorteil sein.The temperature during the elution according to the method according to the invention is not critical. The elution should expediently be carried out at room temperature, that is to say in the temperature range from 15 to 25.degree.

Das erfindungsgemäße Verfahren besitzt gegenüber der bekannten Elution mit verdünnter, wäßriger Ammoniaklösung wesentliche Vorteile. Wie aus Tabelle I ersichtlich, kann die benötigte Menge an Elutionsmittel drastisch reduziert und damit der zeitbedarf bis zur Entladung des Anionenaustauschers verkürzt werden. Dabei wird die Ausbeute an zurückgewonnener fluorierter Emulgatorsäure erhöht. Sie ist in vielen Fällen nahezu quantitativ. Durch die erfindungsgemäße Verwendung von verdünnten anorganischen Mineralsäuren im Gemisch mit organischen Lösungsmitteln wird während der Elution gleichzeitig im Falle des Einsatzes eines schwach basischen Anionenaustauschers dieser wieder in seine ursprüngliche Salzform übergeführt. Damit wird die sonst erforderliche separate Regenerierung eines solchen schwach basischen Anionenaustauschers in die Salzform mittels verdünnter Mineralsäure nach jedem Elutionsschritt eingespart.The process according to the invention has significant advantages over the known elution with dilute, aqueous ammonia solution. As can be seen from Table I, the amount of eluent required can be drastically reduced, thus shortening the time required for the anion exchanger to discharge. The yield of recovered fluorinated emulsifier acid is increased. In many cases it is almost quantitative. Through the use according to the invention of dilute inorganic mineral acids in a mixture with organic solvents, when a weakly basic anion exchanger is used, this is converted back into its original salt form during the elution. This saves the otherwise necessary separate regeneration of such a weakly basic anion exchanger into the salt form by means of dilute mineral acid after each elution step.

Die Abtrennung und Wiedergewinnung von fluorierten Emulgatorsäuren hat Bedeutung vor allem bei wäßrigen Lösungen, die bei Fällungs- und Koagulationsvorgängen im Zuge der Aufarbeitung von Emulsionspolymerisaten fluorhaltiger Monomerer, also vor allem Homo- und Mischpolymerisaten des Tetrafluorethylens, Vinylidenfluorids, Vinylfluorids und Trifluorchlorethylens, aber auch von in wäßriger Emulsion gewonnenen Fluorcarbon-Telomerwachsen anfallen. Desgleichen kann die Abtrennung und Wiedergewinnung fluorierter Emulgatorsäuren auch aus wäßrigen Lösungen vorgenommen werden, die bei Aufkonzentrierungsprozessen von Fluorpolymerisat-Latices gewonnen werden, insbesondere bei solchen Aufkonzentrierungsverfahren, die unter Schichtentrennung verlaufen. Soweit in solchen wäßrigen Lösungen noch Reste von Katalysatoren, anorganische Salze oder nichtionische Dispergiermittel, wie beispielsweise alkoxylierte Alkylphenole oder alkoxylierte aliphatische Alkohole oder Alkylenoxid-Blockpolymerisate, enthalten sind, stören sie die Adsorption und auch die Elution nicht.

Figure imgb0001
The removal and recovery of fluorinated emulsifier acids is particularly important in the case of aqueous solutions which are involved in precipitation and coagulation processes in the course of working up emulsion polymers of fluorine-containing monomers, that is, above all homopolymers and copolymers of tetrafluoroethylene, vinylidene fluoride, vinyl fluoride and trifluorochloroethylene, but also of aqueous emulsion obtained fluorocarbon telomer waxes. Similarly, the separation and recovery of fluorinated emulsifier acids can also be carried out from aqueous solutions which are obtained in the concentration processes of fluoropolymer latexes, in particular in those concentration processes which proceed with delamination. To the extent that residues of catalysts, inorganic salts or nonionic dispersants, such as, for example, alkoxylated alkylphenols or alkoxylated aliphatic alcohols or alkylene oxide block polymers, are present in such aqueous solutions, they do not interfere with the adsorption and also the elution.
Figure imgb0001

In beiden Fällen wurde die Adsorption der Perfluoroctansäure mit Hilfe der durch Behandlung mit verdünnter Salzsäure hergestellten Chloridform eines schwach basischen Anionenaustauschers (MP 62, Hersteller Bayer, Leverkusen) durchgeführt. Abmessungen und Füllungsgrad der Austauschersäule sind in der folgenden allgemeinen Arbeitsvorschrift angegeben.In both cases, the adsorption of perfluorooctanoic acid was carried out using the chloride form of a weakly basic anion exchanger (MP 62, manufacturer Bayer, Leverkusen) prepared by treatment with dilute hydrochloric acid. The dimensions and degree of filling of the exchange column are specified in the following general working instructions.

Die nachfolgenden Beispiele sollen die vorliegende Erfindung näher erläutern, ohne diese damit in ihrem Umfang einzuschränken.The following examples are intended to explain the present invention in greater detail without restricting its scope.

ArbeitsvorschriftWorking procedure a) Adsorptiona) Adsorption

Falls nicht anders vermerkt, wurden 200 cm3 des schwach basischen Anionenaustauschers MP 62 (Hersteller : Bayer AG, Leverkusen) in eine, mit Glasfritte versehene, zylindrische Glassäule (Länge : 64 cm ; Durchmesser : 20 mm) gegeben und durch Spülung mit 800 cm3 1 n Mineralsäure in die in Tabelle II, Spalte 2, angegebene Salzform übergeführt. Anschließend wurden 2 I einer 70 g Perfluoroctansäure enthaltenden, mit verdünntem Ammoniak auf pH 4 eingestellten wäßrigen, aus der Polytetrafluorethylen-Polymeraufarbeitung stammenden Lösung innerhalb einer Stunde über den Austauscher geleitet, wobei die in der Tabelle II, Spalte 3, angegebene Menge auf der Säule adsorbiert wurde.Unless otherwise noted, 200 cm 3 of the weakly basic anion exchanger MP 62 (manufacturer: Bayer AG, Leverkusen) were placed in a cylindrical glass column provided with a glass frit (length: 64 cm; diameter: 20 mm) and rinsed at 800 cm 3 1 n mineral acid converted into the salt form given in Table II, column 2. Then 2 l of an aqueous solution containing 70 g of perfluorooctanoic acid, adjusted to pH 4 with dilute ammonia and coming from the polytetrafluoroethylene polymer workup, were passed over the exchanger within one hour, the amount indicated in Table II, column 3, being adsorbed on the column has been.

b) Elutionb) elution

In Tabelle II, Spalte 4, finden sich Angaben über Zusammensetzung und Menge des Elutionsgemisches sowie den Zeitbedarf bis zur Erreichung des angegebenen Perfluoroctansäure-Elutionsgrads. Das Eluat bestand in der Regel aus zwei Schichten, von denen die spezifisch schwerere untere Schicht in allen Fällen nahezu die gesamte Perfluoroctansäure enthielt. Diese wurde von der überstehenden Schicht abgetrennt, mit 2 n NaOH neutralisiert und durch Einrühren in 1 000 cm3 2 n Salzsäure zur Fällung gebracht. Die ausgefallenen Perfluoroctansäurekristalle wurden anschließend filtriert, mit verdünnter Salzsäure gewaschen und getrocknet.

Figure imgb0002
In Table II, column 4, information on the composition and amount of the elution mixture and the time required to reach the specified level of perfluorooctanoic acid can be found. The eluate generally consisted of two layers, of which the lower layer, which was heavier in specific cases, contained almost all of the perfluorooctanoic acid in all cases. This was separated from the supernatant layer, neutralized with 2N NaOH and precipitated by stirring in 1,000cm 3 2N hydrochloric acid. The precipitated perfluorooctanoic acid crystals were then filtered, washed with dilute hydrochloric acid and dried.
Figure imgb0002

Claims (5)

1. Process for eluting fluorinated emulsifier acids adsorbed on basic anion exchangers, which is characterised by eluting the adsorbed fluorinated emulsifier acid from the anion exchanger with a mixture of a dilute mineral acid and an organic solvent.
2. The process of claim 1, which is characterised in that 0.5 to 10 N mineral acid is used in admixture with an organic solvent and the proportion of aqueous mineral acid to organic solvent is in the range of from 1 : 0.25 to 1 : 20.
3. The process of claims 1 and 2, which is characterised in that the fluorinated emulsifier acid to be eluted is a perfluorocarboxylic acid of the formula CF3(CF2),COOH in which n is a number from 3 to 10.
4. The process of claims 1 to 3, which is characterised in that hydrochloric acid is used as dilute mineral acid.
5. The process of claims 1 to 4, which is characterised in that the organic solvent is miscible with water to an extent of at least 40 % by volume.
EP80100470A 1979-02-02 1980-01-30 Process for the recovery of fluorinated emulsifying acids from basic ion exchangers Expired EP0014431B1 (en)

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DE2903981 1979-02-02

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61215346A (en) * 1985-03-14 1986-09-25 イー・アイ・デユポン・デ・ニモアス・アンド・カンパニー Collection of surfactant
US4609497A (en) * 1985-03-14 1986-09-02 E. I. Du Pont De Nemours And Company Process for separating surfactants used in the manufacture of concentrated fluoropolymer dispersions
US4639337A (en) * 1985-03-14 1987-01-27 E. I. Du Pont De Nemours And Company Process for separating surfactants from liquid used in the manufacture of concentrated fluoropolymer dispersions
US4623487A (en) * 1985-03-14 1986-11-18 E. I. Du Pont De Nemours & Company Process for recovery of fluorosurfactants
FR2597511B1 (en) * 1986-04-17 1990-09-07 Atochem FUNCTIONALIZATION OF IODO-POLYFLUOROALCANES BY ELECTROCHEMICAL REDUCTION AND NOVEL FLUORINATED COMPOUNDS THUS OBTAINED
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DE102014100694A1 (en) * 2014-01-22 2015-07-23 Friedrich-Alexander-Universität Erlangen-Nürnberg Process and apparatus for separating fluorinated hydrocarbons from an aqueous phase
EP3423188B1 (en) * 2016-03-04 2020-01-22 3M Innovative Properties Company Method for removing perfluorinated alkanoic acids
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Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2664441A (en) * 1951-07-19 1953-12-29 Harry S Owens Separation of organic acids
US2863889A (en) * 1956-09-18 1958-12-09 Du Pont Method for recovering fluorinated stabilizer
BE567852A (en) * 1957-05-21
GB1314607A (en) * 1969-09-12 1973-04-26 Kureha Chemical Ind Co Ltd Method for recovering perfluorinated emulsifiers
US3882153A (en) * 1969-09-12 1975-05-06 Kureha Chemical Ind Co Ltd Method for recovering fluorinated carboxylic acid
DE2407834A1 (en) * 1974-02-19 1975-09-04 Kali Chemie Ag PROCESS FOR SEPARATION AND PURIFICATION OF PERHALOGCARBONIC ACIDS CONTAINING FLUORINE AND CHLORINE
DE2754457A1 (en) * 1977-12-07 1979-06-13 Hoechst Ag Per-fluoroalkane sulphonic acid prodn. - by treating soln. of corresp. salt with acid ion-exchanger

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